Automatic fire and change-over dowser



Jan. 10 1950 L. MANNON AUTOMATIC FIRE AND CHANGE-OVER DOWSER 4 Sheets-Sh eet 1 Filed May '7, 1946 INENTOR. lzdam 0112 Jan. 10, 1950 L. mmmmw I AUTOMATIC FIRE AND CHANGE-OVER DOWSER 4 Sheets-Sheet 2 Filed May 7, 1946 ATTOREZEYJ Jan. 10, 1950 L. MANNON AUTOMATIC FIRE AND CHANGE-OVER DOWSER 4 Sheets-Sheet 3 Filed May '7, 1946 AMPL/F/ER INVENTOR. LL oxoMlm am M am,

AYTUF/VEXJ' Jan. 10, 1950 L. MANNON AUTOMATIC FIRE AND CHANGE-OV ER DOWSER Sheets-$heet 4 Filed May '7, 1946 INVENTOR. ZLOYDM VOJY I vb Patented Jan. 10, 1950 AUTOMATIC FIREAND oHANGE=ovEiR DOWSER Lloyd Mannon, San Francisco, Calif Application May 7, 1946, Serial N0: 667,984

2 Claims. (01. 88 -17) 1 An object of my invention is to provide an automatic safety control in which a dowser is automatically held closed until the moving picture film is moving past the film aperture at a speed which will prevent the film from catching fire from the intense heat of the light rays. The

an automatic safety control in which the dowser actuating apparatus and the speed sensitive device operated by the moving film are attachable as units to a moving picture projector.

Still a further object of my invention is to pro vide a dowser actuating means which will also operate a switch that controls the sound circuit so that a closing of the dowser will open the switch and result in the instant silencing of the sound producing mechanism.

The invention also makes use of a 'novel fire shutter actuating mechanism in which the current flowing to the coils that move the solenoid is reduced to a negligible amount as soon as the solenoid has completed its movement and libel solenoid may be kept in continuous use without danger of fire.

A further object of my invention is to provide a speed-sensitive device dependent on the speed and movement of the film through the projectors,

that will automatically close the 'dow'ser, open the sound circuit and motor circuit and will continue to excite the closing solenoid of the dowser, thus holding the dowsers shut until the projector is once again operating in a safe and normal manner.

Other objects and advantages will appear in the following specification, and the novel features of the device will be particularly pointed out in the appended claims.

My invention is illustrated in the accompanying drawings forming a part of this application, in which:

Figure 1 isa front elevation of the dowser actu- 'ating mechanism;

Figure 2 is a vertical section taken along the line 11-11 of Figure 1;

Figure 3 is a vertical section taken along the line III III of Figure 1;

Figure 4 is a top plan view when looking in the direction of the arrows IVIV of Figure 1;

Figure 5 is a longitudinal section taken along the line V-V of Figure 4;

Figure 6 is a horizontal section through Figure 3 and shows the armature in elevation;

Figure 7 is a vertical section taken along the line VII--VII of Figure 6;

Figure 8 is a perspective view of one end of the armature;

. Figure 9 is a horizontal section taken along the line IX--IX of Figure 8;

Figure 1c is a plan view of the film actuated spool and associate mechanism;

Figure 11 is a front elevation of Figure 10 and illustrates the switch containing box with its cover removed;

Figure 12 is a horizontal section taken along the line XII-XII of Figure 11;

Figure 13 is a view looking in the direction of the arrows XIIIXIII of Figure 10 with the cap disc removed;

Figure 14. is a longitudinal section through the speed'sensitive device of Figure 12;

Figure 14a is a perspective view of the cap disc;

Figure 141) is a transverse section taken along the line XIV b-XIVb of Figure 14;

Figure 15 is a View of the motion picture projector showing the automatic fire shutter and the speed sensitive spool operatively applied in place;

Figure 16 is a wiring diagram; and

Figure 17 is a wiring "diagram of two moving picture projectors which are designed to operate consecutively.

While I have shown only the preferred form; of my invention, it should be understood that various changes of modification may be made within the scope of the appended claims without departing from the spirit and scope of the invention.

In carrying out my invention, I make use of a moving picture projector indicated generally at A and this projector has a front wall I and a rear wall 2. My double solenoid for the dowser is indicated generally at B and is applied to the rear wall 2 in a manner hereinafter described. The double solenoid is illustrated in detail in Figures 1 to '8, inclusive. On the front wall 1, I support a film control spool and this spool has a mechanism for actuating a switch. The film controlled spool is shown at C in Figure 10 and the switch is indicated generally at D in the same figure. Both the spool and switch are illustrated in detail in Figures 10 to 14, inclusive, and they are applied to the front wall I of the projector A.

I will first describe the double solenoid and how it operates the dowser. In Figure l I show a plate E with an aperture 3 that registers with a film opening 4 in the rear projector wall 2. Screws 5 or other suitable fastening means are used for securing the plate E to the rear wall 2. The plate E has a bracket 8 secured thereto and the bracket supports a double solenoid B. Before describing the structure of the solenoid, it is best to state that the plate E has a guideway I for slidably receiving a dowser F. The dowser has its upper end pivotally secured to a bellcrank lever B and this lever is pivoted at 9 to the bracket 6. The lever has a notch l therein for receiving the end of a leaf spring ll when the lever raises the dowser to uncover the aperture 3. The free end of the lever is forked at i2 and slidably receives a pin l3 which is carried by a plunger rod l4.

Figure 6 shows how the plunger rod [4 is secured to a laminated armature l5 that is free to reciprocate between two solenoid coils l6 and H. A second rod i8 is secured to the free end of the armature i5 and this rod extends through a laminated solenoid'frame l9. Figure 1 shows the rod l8 as carrying a detent 20 or wiper member that slides along a flexible switch arm 2| and the latter member is used for closing a switch 22 when the armature is moved for opening the dowser F. The switch 22 controls a sound circuit for the moving picture projector and this switch must be closed before the sound reproducer can function.

Figure 5 shows the laminated electro-magnet l9 provided with a guide 23 in which the laminated armature I5 is free to reciprocate. Figure 8 shows the laminations in the armature I5 and Figure 9 illustrates how the rod [8 is secured to a plate 24 which in turn is connected to the armature IS in the manner illustrated. The rod [4 is secured to the armature in a similar manner.

When the coil [6 is energized by a circuit herein after disclosed, the armature l5 will be moved to the right in Figure l and the rod l4 will be moved into the broken line position and will close the dowser F. This movement will carry the wiper 20 along the flexible switch arm 2| and this arm will be swung into the broken line position shown in Figure 1 for opening the switch 22 and breaking the circuit to the sound circuit. A closing of the dowser F will therefore stop the sound reproducing mechanism.

When the coil i6 is deenergized and the coil 11 energized, the plunger rod IE will be moved to the left by the armature i5 that will be attracted to the coil ll. This movement will cause the plunger rod E4 to open the dowser and the wiper member 20 to close the switch 22. Figure 1 illustrates how the dowser F is swung from closed position, indicated by the broken lines, into the open position, indicated by the full lines. A leaf spring I l engages with the notch to yieldingly hold the dowser in open position. The solenoid coils I6 and !'i will draw little current when the armature is drawn into the energized coil because the armature will act as a path for the flux and less current will be required to sustain the fiux field, also the fact that no air gap exists between the armature and field, aids in reducing the consumption of current and permits a continuous operation of the solenoid. The shape of the armature is rectangular so as to prevent it from turning on its axis. Other shapes may be used such as oval or rectangle. side motion or any incidental lateral movement that would interfere with the positive operation of the wiper arm on the flexible arm 2 I.

In Figures 10 to 14, inclusive, I show the film control spool 0 and the mechanism for actuating the switch D when the spool rotates below a predetermined speed or stops. The spool C has two annular rows of teeth 25 for entering the apertures, not shown in the moving picture film. The film as it moves past the spool will rotate it and when the film is moving at the proper speed, which is about ninety feet per minute, the spool will be rotated at a speed which is sufficient to actuate a speed sensitive device shown generally at Gin Figures 12, 14 and 14b.

The spool C rotates freely on a hollow shaft 2'5 that in turn is supported by a casing 21. The casing is carried by a tubular support 28 and this support has a threaded portion .29 that enters an opening 30 provided in the front wall I of the projector. A switch box 31 has an opening for receiving the tubular support 28 and lock nuts 32 and 33 are mounted on the threaded portion 29 for locking the switch box and the tubular support to the front projector wall I. The support has a switch carrying bracket 34 connected thereto and the switch D is secured to the bracket. Figure 11 shows the switch with a flexible arm 35 that bears against a rod 36 which in turn is slidably mounted in the tubular support 28 as will presently be described.

A rotation of the spool C will rotate a housing 31 that contains the speed sensitive device. This housing encloses a rotatable base 38 to which are pivotally mounted flyweights 39. The base rotates with the spool C and has fiat sides. L- shaped arms 40 are secured to the flyweights and are pivoted at 4| to the base 38 that is rotated by the spool C. The base has a tubular extension 38a with a non-circular outer surface on which a friction disc 42 is slidably mounted. The disc is rotated by the tubular extension 38a and has parallel and longitudinally extending fingers 43 that straddle the tubular extension 38a. The free ends of the L-shaped arms 40 are pivotally connected at 40a to the fingers 43 so that an outward movement of the fiyweights 39 caused by the rotation of the spool C at the proper speed will move the fingers and the friction disc 42. The

(0 disc will frictionally engage with the second friction disc 44 with a leather facing.

The two discs form a clutch and when the rotating disc 42 contacts the disc 44, the latter will be rotated and will cause its central shaft 45,

5 see Figure 13, to turn and to turn a cam 46 that in the casing 21 and the other end of the spring Such armature shapes will prevent is connected to a pin 50 mounted on the cam. Should the spool C slow down to a point where the disc 42 will be freed from the disc 44, the spring 48 will return the cam to its initial position and permit the rod 36 to be moved by the spring arm 35, whereupon the switch D will be opened. A pair of coil springs 5! are used for moving the disc 42 out of frictional engagement with the disc 44. The speed sensitive device shown in Figure 12 is somewhat the same as that shown in my copending application, Serial No. 650,008, filed February 25, 1946. Figure 14a shows a cap disc '52 that is placed over the open end 53 of the casing .2! for closing the casing. The cap disc 52 has a notch 54 therein that permits the end of a tool to be forced into the notch when freeing the disc from the casing 21.

Figure 15 shows the relation between the double solenoid B, the spool C and the switch D. The

projector is not altered in any way when attaching the solenoid spool and switch thereto, except to provide the opening 36 in the front projector wall i for receiving the tubular support 28. The film in being passed through the projector has a portion held. in contact with the spool (3 so that the moving of the film will rotate the spool. This contact is made below the intermittent sprocket We, see Figures 16 and 18, and before the lower feed sprocket 28b, and the loop in the film comes before the film controlled sprocket C so as to remove the jerks in the film caused by the intermittent sprocket. In locating the sprocket C in this position, the film is held in contact with the sprocket by the tension that is created in the film due to the mounting of the sprocket above the normal path of the film (see broken line position in Figure 15) as it moves to the lower feed sprocket 2819. This will permit the film to leave the sprocket C at the slightest pause in its path past the picture aperture. The idler roller 280 that holds the film down on the feed sprocket 2% also aids in keeping the film N in contact with the sprocket C.

In Figure 17, I show a Wiring diagram wherein my device is used on two projectors that are designed to alternate with each other in the showing of a picture. The moving picture projector motor or coth machines is indicated at M in Figure 1'7 and the motor for each projector is connected to a source of current 55 by a main motor switch 56. Since each projector is identical with the other, corresponding reference numerals will be given to both, except that the reference numerals will be followed by the letter a in the projector shown at the left hand side of Figure 17.

A pilot lamp 5? is shown in parallel with the motor M and the source of current 55 and this lamp is illuminated when the motor is operating. It will be seen that a relay actuated switch 58 is in series with the motor circuit and this switch is closed until its relay 5%? is energized, at which time the relay switch fit will open. A motor push button momentary starting switch 66 is adapted to shunt out the relay switch 58 for initially starting the motor and the switch 69 can be depressed by the operator and will connect the motor to its source of current whereby the projector will be brought into operation.

Before describing the rest of the wiring diagram, it is best to state that the moving picture film N is fed from a feed reel 5| to a take-up reel and the film passes by the film aperture 3 in the rear wall '2 and then passes around the intermittent sprocket 28a, past the film control sprocket C, and from there it moves past the lower feed sprocket 28b, and through the sound reproducing mechanism indicated by a fotoelectrio cell 53 and an exciter lamp 64. All of this mechanism is standard, except the spool C. The speed sensitive device G is shown diametrically connected. to the spool C in Figure 1'7 and it operates the switch D in the manner already described. In the wiring diagram, a bellcrank lever is shown operating the switch D, although in actual practice the mechanism shown in Figures to 14, inclusive, will be used for this purpose. When the projector is not operating the switch D is closed.

The source of light for each projector, such as the electrodes 65, are shown connectable to a source of current 65. A light switch 61 connects the electrodes to the current source and this same switch connects the relay 59 to the same source oicurrent. In other words, the relay will be energized only when the electrodes $5 are energized. As already stated, the switch D is closed when the projector is not operating and therefore the circuit from the relay 59 to the current source 66 Will be closed.

In Figure 1'7 assume that the right hand projector is operating and that the left hand projector is not running, but the light is on and the projector is ready to start. On the left hand projector the control spool C is not revolving and therefore the speed sensitive device G is not operating. Switch D is normally closed and the relay switch that will be closed because the relay Eta is energized. This will cause the closing solenoid lla to hold the dowser F closed over the film aperture 4a. The relay switch 12a is open and disconnects the closing solenoid Ila on the left hand projector from the opening solenoid is on the right hand projector so that there is no interference should it be necessary to close the dowser F on the right hand projector, or should it already be closed.

To start the left hand projector in operation, the switch 56a is closed, which will light the pilot light 5%, indicating that the momentary switch 69a will operate. Switch 66a is now closed and connects the motor M with the source of current 55a. Film N moves from the feed reel tic, past the film aperture 4a, over the intermittent sprocket 2811, the control spool C, over the feed sprocket 231), between the exciter light Eta and past the photo-electric cell 63a to the take-up reel 62a. The control spool C is rotated by the passing film and when the film is moving at a safe speed, the speed sensitive device G opens the switch D, deenergizing the relay 59a which opens the relay switch 68a and deenergizes solenoid Ha. At the same time relay switches 72a and 58a are closed. Relay switch 58a connects the motor M to the source 55a and will now carry the current to the motor. Relay switch 72a connects the opening coil Mia on the left hand projector to the closing solenoid IT on the right hand projector so that now when switch 13a is closed solenoid 16a will open the dowser F on the left hand projector and will simultaneously close the sound switch 2211 while at the same instant the solenoid I i will close the dowser F on the right hand projector and will open the sound switch 22. This will result in an instantaneous change of picture and sound on the screen from one projector to the other and give a complete automatic safety control from the spools C' at all times.

Should any failure in the right hand projector take place to cause a slowing down or a stopping of the film, the speed sensitive device G will instantly close the switch D to energize the relay 59 to close switch 68 and open switches 58 and 12. The closing of switch 68 will connect dowser closing coil I! in the right hand projector with the dowser circuit wires 69 and i9 and the dowser F will immediately close and shut off the light rays to the film N, also opening sound switch 22. At the same time the opening of switch 58 will disconnect the motor M from its source of current so the projector will come to a stop. The solenoid I! will continue to be excited until the film in the right hand projector is fixed, the starting button to can be depressed and when the film is moving at a safe speed, the relay 59 will be deenergized, the switch 68 will open and the switches 58 and 12 will close. The starting cycle will again repeat itself in the manner explained.

In Figure 16, I show a Wiring diagram for one moving picture projector in which my invention is used. This wiring diagram makes use of the same current source I25 for the source of light, such as a Mazda light or electrodes 55, and for the coils I6 and I! of the double acting solenoid B. A closing of a switch I26 to connect the electrodes with the current source will also connect the closing solenoid with the same source so that the arc supply circuit becomes the control circuit for the dowser F. This holds the dowser F shut until the film N passes from the film feed reel 6| to the film take-up reel 62. the film aperture 4 and actuates the film control spool C. The spool rotation controls the governor G and the latter actuates a two-way switch I21. When the'spool C is idle, the switch I21 will connect the dowser-closing solenoid coil I6 with the current source I25 when the arc supply circuit switch I26 is closed. This will energize the coil and move the dowser F over the film aperture 4. The sound circuit switch 22 is also opened.

A manual closing of the momentary switch I 28 will connect the projector motor M with its source of current I29. Of course, the main motor switch I30 is first closed, but this switch is in series with the switch I28 so both must be closed before the motor will initially start. As soon as the motor and film moving mechanism come up to the proper speed, the film N will cause the spool C to operate the governor G to close the switch D. The closing of the switch shorts the momentary switch I28 and permits the operator to free it. The motor M will continue to operate so long as the film moves at the proper speed past the film aperture 4.

The governor G also actuates the two-way switch I21 to cut out the coil I6 and to connect the coil IT with the current source I25. The coil I 'I will be energized and will lift the dowser F. At the same time the plunger rod i8 will close the sound circuit switch I8. now under full operation with the light from the electrodes 65 throwing the moving picture from the film N onto the screen, not shown, after passing through the lenses I3I Should for any reason the film not be moved at the desired speed or should the film break or stop, the governor will instantly slow down or stop and open the switch D to cut out the motor M. At the same time the two-way switch I21 will be actuated to cut out the coil I1 and connect the coil I6 to the current source I25. This will close the dowser F to protect the film from the light rays and open the sound circuit switch 22. The film is thus protected from fire.

The solenoid circuits only become active when the electrodes are connected which is the only time a fire danger could arise for the film. So long as the film is moving at the proper speed, the dowser F will remain raised, but the instant anything goes wrong with the projector which will result in a slowing down or a stopping of the film, the dowser will immediately close to protect the film from fire, the sound circuit will be opened and the projector motor will stop.

The film passes The projector is I claim:

1. In a device of the type described, a motion picture projector having a film movable therethrough, a source of light for projecting light rays through the film, a source of electric current for the source of light and including a switch, a light shield, a solenoid for closing the light shield, a film-actuated safety device, electric means controlled by the safety device for en ergizing the solenoid and closing the light shield, said means being connected to the light circuit for making said means active when the light source is connected to its current source, whereby the light shield is closed whenever the light source is connected to its current source and the film is not moving through the projector in a safe and normal manner.

2. In a device of the type described, amotion picture projector having a film movable therethrough, a source of light for projecting light rays through the film, a source of electric current for the source of light and including a switch, a light shield, a double-acting solenoid operatively connected to the light shield and having a coil which when energized will close the shield and having another coil which when energized will open the shield, a film-actuated safety device, electric means controlled by the safety device for energizing the closing coil and closing the light shield, said means being connected to the light circuit for making said means active when the light source is connected to its current source, whereby the light shield is closed whenever the light source is connected to its current source and the film is not moving through the projector in a safe and normal manner, said electric means deenergizing the closing coil and energizing the opening coil for opening the shield as soon as the film moves through the projector in a safe and normal manner.

LLOYD MANNON.

REFERENCES CITED The following references are of record in the file of this patent:

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